Circular knitting machine



May 6, 1941.

J. c. H. HURD CIRCULAR KNITTING MACHINE Filed ma 10, 1940 6 Sheets-Sheet1 May 1941' J. c. H. HURD 2,241,134

CIRCULAR KNITTING MACHINE Fil'ed May 10, 1940 6 Sheets-Sheet 2 Fig. 2.

May 6, 1941.

J. c. H. HURD 2,241,134

CIRCULAR KNITTING MACHINE Filed May 10, 1940 e Sheets-Sheet s Fig. 2A

y 1941- J. c. H. HURD 2,241,134

CIRCULAR KNITTING MACHINE v Filed May 10, 1940 6 Sheets-Sheet 4 May 6,1941.

J. c. H. HURD CIRCULAR KNITTING MACHINE Filed May I0, 1940 6Sheets-Sheet 5 May 6, 1941. J. c. HQHURD CIRCULAR KNITTING MACHINE Filed May 10, 1940 6 Sheets-Sheetfi ,4. Wm,m.;

Patented May 6, 1941 u NIT ET ESTATES PATENT CIRCULARKNITTING :MACHIN EJohniCyriLHerbertHurd, Leicester, 'Englanias: signor to'Wildtand'Company Limited, Leicester, England,:a British companyApplication May;10, 1940, Serial-No. 1334;445 In Great BritainMay16,1939

13 Claims.

The invention is intendediorapplication-principally :to machines of the:kind having superimposed rotary needle cylindersiurnishedwithdoubl-e-endedmeedles operable hymeans ofislidersas exemplified in thespecifications of UnitedKingdom of Great BritainLetters Patents Nos.24,290 of 1912 and 391,212.

Further, the invention is "applicable :to .machines of l the aforesaid:characteristicrtype haying two or more feeders and provision:torautomatica'lly effecting changes .such, for example, as are Ioperating, e. g. withdrawingirom oraputtinginto action or adjustingmac'zhinecams "for aoperait- I ing the needles, 'or their associatedsliders in a machine having double-ended; needles.

The invention, moreover, concerns "principally the operation of theiwelt cams :of :the .machineialthough it may be .extended to theoperation of other machinecam's, such for example as transfer cams andstitch oams, "especially stitch cams conjointly.with'theweltcams.

The present invention, :then, comprises atsimple arrangement ofmechanism foraoper-ating the maohinecams as will behereinafterdescribed.

A practical arrangement constituting one example of the invention .asapplied 170 a circular knitting machine of the-superimposed rotary:needle cylinder type will presently be described.

In the accompanying drawings,

Figure 1 is a general perspective :view, .olrawn diagrammatically, of somuchof the machine as is necessary to illustrate the application theretoof the said invention,

Figures :2 and 2a together constitute :a plan view .of the.relevant-parts of the machine,

Figure 3 is a detail plan View illustrating a modification hereinafterto 'be described,

Figure 4 is an elevational view-iof intermediate 7' connections employedin the operation of stitch cams conjointlywit'h a weltrcam,

Figure 5iis a developed'lay-out'of :aportion of the ecam isystem of "themachine-tat two :adj acent seeds-purporting Zto show some 0f :the,machine r cams which are operatedbythe improved mechanism, and

.-Figure5a. isa view similar to Figure Bshowing the remainder of the camsystem.

Like parts are designated -by similar reference characters-throughoutthe drawings.

:Now the invention includes an arrangement of operating-cams, for anyparticular set of two @or more machine cams, in one plane-and anarrangement .of cam pieces or like elements'on -a control drum,ring-orlike body suchwisethat just prior to the commencement of a cycleof operations of the said set of the machine cams the corresponding campieces -01 like elements are respectively at difierent-angulardistances,equivalent to different'numbers of racks of the drum, ring or like body,from the points of operation of the machine cams. Thus with the firstcam piece -or like element the distance of one rack "from the pointofoperation of the corresponding machine camorcamsthe next cam piece orlike element would be two racks -from the point of operation ofthenext-machine cam or cams inthe same-set and soon according to the numberof points ofoperation and cam piecesor like elements provided. Forexample, in thecase of a four feeder machinehaving a set of four weltcams or transfer cams the fourth cam piece or likeelementunder theconditions aforesaidwould be four racks away from th point of operationof :the fourth machine cam while-the first campiece-iorlike:elementwould be but one rack away .from thepointofoperationof the first machine cam.

As will .be understood, by a rack is meant the angular distance throughwhich the control drum, ring or like body is turned or racked bytheaction of an operating cam inthe intermedi- :ate "connections. Theremay be in the same .series of operating cams in one plane difierentoperating cams for different sets of machine "cams, and accordinglythere may be differentsets of cam pieces or like-elements arranged'asaforesaid onthe control drumor like body. Alternatively, there may bedifferent sets of operating cams and difierent setsof cam pieces'or likeelements arrangedin the way described for different setsof'machine cams.

In Figure 1 of the drawings superimposed 'rotary plainorbottom and ribor top needle cylinders are indicated-at I and 2 respectively. Thebottom cam box, which-is secured to the bottom :plate -3 of'the machine,is represented at 4, while thetop canrbox, shown :at 5, depends from-andis attached :to "the underside of the customary top plate 6, all inaccordance with conventional design.

According to the arrangement illustrated operating cams, such as thoseshown at I, B, 9, l0, II and I2 (see Figure 2) are mountedcircumferentially and at the same level on the cylinder driving gear(not shown) or otherwise associated with the bottom needle cylinder Iand cam pieces or like elements such as those represented at I3, l4, I5,I6, I! and I8 are mounted in a control unit in the form of a groovedring I 9 mounted on the aforesaid top plate 6. The operating cams, whichare therefore all in one plane beneath the bottom plate 3, mayconveniently be secured within a circumferential groove in a hub or likeintegral part of the conventional bevel driving gear. association withthis cam arrangement there is provided a lever 20 fitted with a camroller 2| for contact with the operating cams at desired times. Thislever is mounted on a vertical rack shaft 22 to which is attached thepawl lever 23 of a pawl and ratchet mechanism for racking the controlring I9. 7

The lever 20, moreover, is held normally inoperative, that is to say inthe position shown in Figures 1 and 2, until required changes are to beeffected by means of a catch 24 adapted to be operated, to release thelever, from the existing timing or controlling mechanism of the machine,or from an auxiliary unit such as a separate timing chain. In thespecific example depicted in Figures 1 and 2, the catch 24 consists ofa'pivoted lever which is mounted be- 'neath the bottom plate} and formedwith a protuberant claw-like formation 24a. adapted for engagement atappropriate times with a pin or projection 25 provided on the' lever 29.In Figure 1 one of the cam bits on a timing chain is designated at 2B,and the chain itself is racked round in the usual way by pawl andratchet mechanism 21, 2B, the pawl of which is operated by areciprocatory rod 29 fitted with a cam roller 30 for contact with a camor cams (not shown) arranged to revolve about an axis concentric withthe axis of the needle cylinders. The cam bits on the chain are arrangedfor action on one arm of a two-armed pivoted lever 3|, and intermediateconnections such, for instance, as the link 32, the bell crank 33 andthe curved link 34, are provided between said lever and the catch 24. Aswill be understood the catch is arranged so as to engage the lever 20when the latter is moved outwards by the operating cams. Release of thelever 20 is, of course, obtained by turning the catch 24 in ananticlockwise direction, and such a movement is effected each time a cambit 26 engages the toe 3Iaof the lever 3|. Preferably, the connectionsbetween the catch 26 and the lever 3| are spring loaded or controlled.Conveniently for this purpose, a tension spring such as 35 may beanchored at one end to an appropriate portion of the bell crank 33and'at its other end to a pin or peg on the bottom plate 3.

' The rack shaft 22 is mounted to turn in suitable bearings in the topand bottom plates of themachine, and thepawl lever 23 is rigidlyattached to the extreme upper end of said shaft 22 and the pawl lever 23all turn together, and these parts are spring-controlled. For thislatter purpose there may conveniently be provided a tension spring suchas that depicted at 38 in Figure 1, one end of this spring beinganchored to a convenient part of the lever 20 while the opposite endthereof is anchored to a pin or projection 39 secured in the bottomplate 3. Now, assuming the machine to be in operation and the catch 24to have been actuated suchwise as to effect release of the lever 20,then each time one of the operating cams l-l2 engagesthe roller 2! thelever 29 will be moved outwards with the result that the rack shaft 22together with the pawl lever 23, will be turned in an anti-clockwisedirection-against the action of the spring 38thereby imparting anoperative stroke to the pawl 35. Immediately an operating cam passes theroller 2|, however, the lever 20 will be pulled inwards under theinfiuence of the spring 33 so that the pawl lever 23 is caused to make areverse, i. e., idle, stroke. Each time a complete operative stroke isimparted to the pawl 36, the control ring [9 will be turned or racked inthe direction of the arrow A to the extent of one step. In Figure 2 theangular distance constituting one rack is indicated at a. If, as shown,there are six operating cams in one plane, then the control ring l9 willbe racked six times at each revolution of the machine. Thus, the totalangular distance through which said ring is turned at each suchrevolution is a 6, i. e. a distance I).

The control ring [9 is formed with a plurality of concentric annulargrooves Na in which the cam pieces or like elements, appropriatelyarranged, are secured by means of screws 40. For the sake of clarity inFigure 2 only six cam pieces are shown, these particular cam piecesbeing employed during a cycle of operations to effect a change from theproduction of a welt to 2/2 rib knitting by operation of the bottom weltcams and top transfer cams in the manner presently to. be described. Itis to be understood, however, that in actual practice the control ringwould be furnished with several other cam pieces or like elements andthat these would be appropriately prearranged so as to enable variousother changes, such as' those mentioned hereinafter, to be effectedduring the production of a garment length or article.

The machine cams to be controlled from the control ring I9 arerepresented in Figures 5 and 5a and will now be described. Theparticular machine with which the present description is concerned hasfour feeders and accordingly the bottom and top cam boxes 4 and 5 areeach made up of four sections. Thus the first and second sections 6 andS of the bottom cam box are shown in Figure 5, while the third andfourth sections S and S of said box are shown in Figure 5a. Similarly,the first and second sections so and Sb of the top cam box are shown inFigure 5. and the third and fourth sections so and Sd of said top boxare represented in Figure 5a. The sections S and So together constitutethe rst feeder of the machine; the sections S and Sb constitute thesecond feeder; the sections S and Se together form the third feeder, andthe remaining two sections constitute the fourth feeder. It will benoted that the third section in each box is identical with the firstsection in said box, and similarly the fourth section is identical withthe second. Now, as will be seen, the first section S of the bottom cambox 4 includes an adjustable. plain stitch cam 41, a bottom welt cam 42which is adapted to control the admission of appropriate slider butts toa welt track 43, and a bottom transfer cam 44. The third section S ofthis box similarly includes a stitch cam 4P, a welt earn 42 a welt track43 and a transfer cam 44 The second section S of the bottom cam boxincludes an adjustable plain stitch cam 45, and the fourth section Sincludes a similar stitch cam .45 The first section So of the top cambox includes an adjustable rib stitch cam 46, and a top transfer cam 41,whereas the third section Sc of this box similarly includes a rib stitchcam 46 and a transfer cam 41 The second section Sb of said top boxincludes an adjustable rib stitch cam 48, a top welt cam 49 adaptedtocontrol the admission of appropriate slider butts to a welt track 50,and two top transfer earns 5| and 52. Finally, the fourth section Sdincludes a stitch cam 48 a welt cam 49 a welt track 58 and two transfercams 5H and 52 The various adjustable stitch cams are each mounted on aslide 53 (see Figure 4). The welt and transfer cams are all of the bolttype movable radially in their cam boxes and spring controlled. Thesebolt cams, moreover, are normally held withdrawn against the springaction and when released spring into their operative positions.

The intermediate mechanisms constituting the points of operation of themachine cams may be of any suitable form. Advantageously, operation of awelt cam is effected conjointly with quality adjustment of adjacentstitch cams at the same feeder for producing slack courses in the welts,for which purpose such welt cam and stitch cams may be operated from thecontrol ring l9 through intermediate mechanism common to both or throughindependent intermediate mechanisms. One form of mechanism through whichrib and plain stitch cams 46 (46 and 4| (4l respectively and a bottomwelt cam 42 (42 are operated conjointly will now be described, by way ofexample, with reference to Figures 2 and 4. As will be seen, then, alever 54 which is pivoted at 55 onthe top cam box 5 has a pin-and-slotconnection 55. 51 with the slide 53 of the rib stitch cam 46 (4 5 Theposition normally occupied by this rib stitch cam is determined by anadjustable stop 53 which is in the form of a screw arranged for contactwith a part of or on the slide 53. The stop 58 is carried by a part 59attached to the cam box 5. The lever 54 is controlled by a tensionspring 60 arranged as shown. Adjustment of the cam 45 (46 is thereforeefiected by turning the lever 54 upwardly on its pivot to raise theassociated slide 53 to the required extent against the spring action.The extent of this movement can be varied by suitable adjustment of thescrew 58, and for facilitating this adjustment there is provided apivoted pointer B! which latter is connected to the rib stitch cam slideand movable in relation to a fixed scale 52 appropriately graduated orcalibrated. The lever 54 is actuated by a rod 63 which extends upwardlycam slide. The position normally occupied by the plain stitch cam isdetermined in the usual wayby an adjustable stop 10. A pivoted pointer Hconnected to the plain stitch cam slide is provided in association withan appropriately graduated or calibrated scale l2. The arrangement istherefore such that whenever the arm 65 and hence also the operating rod63, is lifted, the rib stitch cam will be raised and the plain stitchcam correspondingly depressed, and vice versa, to vary the quality ofthe stitch; the arm 6.5 is appropriately bossed and mounted to turn on ahorizontal spindle I3 which latter is carried in brackets 14 and 15secured to the top plate 6. The outer end of the arm 65 carries a screw16 the leading end of which is arranged in the path of a cam piecesecured within an :appropriate groove l9a in the control ring l9; thiscam piece is not shown. The bottom welt cam 42 (42 located adjacent tothe plain stitch cam 4| is operated by a rod 11 which extends upwardlythrough the top plate 6 and is connected to an arm 18. This arm isindependently mounted on the spindle l3 and rigidly connected by meansof an integral bridge portion 19 to another arm 80. The arm 80, which isalso bossed and mounted on the spindle 13, is furnished with a toe-piece8| arranged in the path of another of the cam pieces on the groovedcontrol ring. The rod 11 is loaded, e. g. by means of a tension springsuch as 82 arranged as shown in Figure 4. At its lower end the rod 11 isconnected to a rotary element 83 which has cam formations adapted to actupon a transverse pin 84 secured in the bolt 85 of the bottom welt camto be operated.- Whenever the toe-piece 8| (81 is lifted by a cam piece,the rod 11 is raised against the action of the spring 82 to effectwithdrawal of the welt cam 42 (42 thereby admitting appropriate sliderbutts to the welt track 43 (43 Conversely, whenever the said toepiece ispermitted to drop off a cam piece under the spring action the welt camwill move in and close the track 43 (43 From a consideration of Figure 2it will be appreciated that the bottom welt cam 42 at the first sectionS of the bottom cam box is operated from the cam piece l3, whereas thecorresponding welt earn 42 at the third section S of said box isoperated from the cam piece l6.

Now, whenever a welt cam is operated the adjacent stitch cams areadjusted conjointly in the appropriate manner. But as will be seen fromFigures 5 and 5a, in each instance a welt cam is spaced apartcircumferentiall'y to a small extent from the corresponding stitch cam.Accordingly, it is necessary to effect adjustment of such stitch camsslightly in advance of the time at which the welt cam is operated. Thus,for instance, just prior to moving in the bottom welt cam 42 (42 it isnecessary to raise the plain stitch cam 4! (M and simultaneously depressthe rib stitch cam 46 (46 To achieve this result the cam piecesconcerned are appropriately arranged upon the control ring 19 and thelatterinstead of being racked round one complete step-is turned two halfracks by the action of a single operating cam upon the cam roller 2!,suchwise as to permit the screw 16 to drop off its cam piece a littleearlier than the toe-piece 8! (8). In this connection the readersattention is directed to the operating cams l, 8, l8 and l I (Figure 2)each of which is stepped for the purpose just mentioned.

Other intermediate mechanisms are also shown in Figure 2. For instance,the top welt cams 49 and 49 are operated by rods 86 attached to arms '81which are rigidly secured to spindles B8. Arms 89 similarly secured tosaid spindles carry toe-pieces 99 and 99 for co-operation withappropriately arranged cam pieces on the control ring I9. The stitchcams 45 and 45 and 48 and 48 to be adjusted conjointly with operation ofthe top welt cams 49 and 49 are actuated from rods 9!. These rods areattached to arms 92 which are suitably bossed and mounted on thespindles 88 independently of the arms 81. As will be appreciated thearms 92 are similar in design and function to the arms 65 aforesaid.With regard to the top and bottom transfer cams these are convenientlyoperated by rods 93 attached to arms such as 94 which are fixed uponspindles 95. Thesespindles are adapted to be rocked at appropriate timesto actuate the rods 93 by the action of cam pieces upon toe-pieces suchas 96 and 96 carried by arms 91 which are also rigidly secured to thespindles 95.

As previously mentioned, for the sake of clarity only six cam pieces arerepresented in Figure 2.

In accordance with the present invention these cam pieces are arrangedon the control ring l9 suchwise that just prior to a change from theproduction of a welt to 2/2 rib knitting, it will require one rack a ofsaid ring to enable the toepiece 8! todrop off the cam piece 13 at thepoint I3a; two complete racks of the ring l9 to enable the toe-piece 96to drop off the cam piece M at the point 14a; three racks of the ringbefore the toe-piece 99 drops off the cam piece [5 at the-point I5a;four racks of the control ring before the toe-piece 8P drops off theappropriate end [6a. of the cam piece [6; five racks of the ring toenable the toe-piece 96 to drop ofi' the end Ila of the canr piece H;and six complete racks (a distance h) before the toe-piece 99 drops offthe end I80, of the cam piece l8.

Bywayof examplethe precise movements which take place during the changelast referred to will now be set forth. Assume that the series ofoperating cams 'I-IZ are rotating in the direchalf rack the screw (shownat the bottom of Figure 2) will drop off a cam-piece thereby effectingsimultaneous adjustment of the stitch cams 4| and 49; at the second halfrack the toepiece 8| will drop off the cam piece I3, with the resultthat the bottom welt cam 42 will move in to close the welt track 43.Next, the cam 52 acts on the roller 2| to impart one complete rack tothe ring l9, and. as a result of this second rack the toe-piece 96 dropsoff the cam piece 14 and the 2/2 top transfer cam 5i moves in. A thirdrack (in two separate movements) is then imparted to the ring 19 byreason of the cam II passing in contact with the cam roller 2!. At thefirst halfof this third rack the appropriate arm 92 is permitted to dropso that the stitch cams and 48 are adjusted. At the second half of saidthird rack the toe-piece 90 drops off the cam piece l5 whereby the topwelt cam 49 is allowed to move in to close the welt track 50. By reasonof the cam l9 next acting on the roller 2|, the ring I9 is once againracked round (the fourth rack) in two separate movements; at the firstof these movements the screw l9 (shown at the top of Figure 2) will dropoif a cam piece to effect adjustment of the stitch cams Al and 46whereas at the second movement the toepiece 8I will drop off the campiece l6 suchwise as to enable the bottom welt cam 42 to move in toclose the welt track 43 The fifth rack of the control ring is obtainedwhen the cam 9 engages the roller 2| at which time the toe-piece 96 willdrop off the cam piece I! to move in the 2/2 top transfer cam 5i.Lastly, the cam 8 will, by action on the cam roller 2|, eifect a sixthrack of the ring l9 in two stages. At the first stage the appropriatearm 92 will be permitted to drop suchwise as to effect simultaneousadjustment of the stitch cams 5 and 49 whereas at the second stage thetoe-piece 99 will drop off the cam piece [8 to allow the top welt cam 49to move in, thereby closing the welt track 59 In elaboration of what hasalready been described, it is considered desirable to make the followingobservations:

The machine illustrated may conveniently be constructed to make a Frenchwelt prior to which several courses of ordinary purl fabric may be madeby causing all the needles to knit in the top cylinder at one feeder andall the needles to knit in the bottom cylinder at the next or adjacentfeeder, and so on.

If, as may be, the machine is furnished with mechanism for inserting adraw thread, then it is atthe last of the purl courses at a feeder whereall the needles are knitting in the top cylinder that the draw thread isactually inserted. The operation of the welt cams, stitch cams and 2/2transfer cams is performed seriatim on a definite slider, i. e. a changeslider, in each of the top and bottom cylinders, when the particularslider is in line with the corresponding welt cam. This change slider isthe first slider to pass along the appropriate welt track. In setting upthe machine the top change slider is inserted one trick in advance ofthe bottom change slider.

At the next, 1. e. first, feeder, when all the needles are in the bottomcylinder, the welt proper is commenced by first effecting adjustment ofthe stitch cams 4| and 46 and then withdrawing the welt cam 42 at thatfeeder.

This welt cam operates on the knitting butts of sliders which are setout with a long butt alternating with a short butt, and when the weltcam is withdrawn it allows sliders having short butts to pass along thewelt track 43 and sliders with long butts to clear in the usual manner.As the bottom transfer cam 44 is in, all those long butt sliders whichcleared transfer their cor responding needles to the top cylinder and inthis manner a 1/1 rib formation is produced from a plain knitted course.At the second feeder, the stitch cams 45 and 48 are adjusted and the topwelt cam 49 is withdrawn. This top welt cam, similarly to the bottomwelt cam 42, operates on the knitting butts of the sliders, which areset out with a long butt alternating with a short butt. The short buttsliders pass along the welt track 50 and as these are carrying theneedles transferred up at the previous feeder, there is a cessation ofknitting at this feeder in the top cylinder. The sliders furnished withlong knitting butts in the top cylinder are not engaged with needles atthis stage.

In the bottom cylinder at the second feeder, all sliders clear so thatthose engaged with a needle cause said needle to knit; that is to say,at this feeder needles which alternate with those in the top cylinderknit.

At the third and fourth feeders, similar action takes place to thatdescribed with respect to the first and second feeders.

The change from welt to 2/2 rib is eifected immediately after a completewelt is made, that is to say, after the machine has made one completerevolution from the commencement of the welt, and the bottom changeslider is once again in alignment with the welt cam 42.

At this stage the Welt cam 42 moves in, and, following the changesliders round the machine, the 2/2 transfer cam moves in.

The transfer butts of the top sliders are set out with two'long buttsalternating with two short butts, and the first two long butts down mustbe at least one slider behind the bottom change slider.

When the change slider is in alignment with the welt cam 49 said cammoves in and, as the cylinders revolve, welt cam 42 then the other 2 2transfer cam 5| and finally the welt cam 49 all move in sequentially sothat the machine is then making 2/2 rib fabric. Normally this'latter ismade at the same quality or stitch length as the welt. I

To efiect a change from 2/2 rib to reverse knitting First, both thebottom and top- 2/2- transfer cams following the first feeder and thecustomary selector unit are simultaneously withdrawn when the 2/2 changesliders are in alignment with the 2/2 top transfer cam 5|. Following themachine round, the stitch cams 45 and 48 are operated at the secondfeeder, then the stitch cams M and 46 are operated at the third feeder,the bottom and top 2/2 transfer cams after the-third feeder arewithdrawn simultaneously, the stitch cams 45 and 48 at the fourth feederare op erated and finally the stitch cams 4| and 46 at the first feederare operated.

Assume now that the control ring l9 has seventy-two teeth and is turnedto the extent of six racks at each revolution of the machine.

Then if, as may be, the machine is set out so that two complete garmentlengths can be produced while the control ring I9 is turned through onewelt cam 42 is withdrawn. The 8th rack is an idle one. At the 9th rackthe stitch cams 45 and 48 are operated and the welt cam 49 is withdrawn.The 10th rack results in operation of the stitch cams 4| and 46 andwithdrawal of the welt cam 42 The 11th rack is an idle one, and at the12th rack the stitch cams 45 and 48 are operated and the welt cam 49 iswithdrawn.

Racks 1 3-1 8 During these racks a change is made from the welt to 2/2rib knitting. This sequence of operations has previously been given indetail, but it is repeated again, briefly, for the sake of continuity.Ihe 13th rack permits of appropriate adjustment of the stitch cams 4|and 46 and allows the welt cam 42 to move in. (Also, the transfer cams52 and 52 are withdrawn at this rack.) The transfer cam 5| moves in atthe 14th rack. At the 15th rack the stitch cams 45 and 48' are adjustedand the welt cam 49 moves in. The 16th rack permits of appropriateadjustment of the stitch cams M and 4E and allows the welt cam 42 tomove in. At the 17th rack the transfer cam 5| moves in, and at the 18thrack the stitch cams 45 and 48 are adjusted and the welt cam- 49 movesin.

Racks 19-24 These six racks change the machine from 2/2 rib to theproduction of patterned work. The 19th rack is an idle one. The 20thrack effects withdrawal of the transfer cams 44' and 5|. At

the 21st rack the stitch cams 45 and 4B are Racks 2 5-3 0 The 25th rackeffects operation of the stitch cams 4| and 46, and the remaining fiveof these six racks are idle.

All of racks 31-36 are idle ones.

Racks 37-72 As will be readily appreciated this second group ofthirty-six racks effects precisely the same changes as those effectedduring racks l-36.

revolution, there will be thirty-six racks for each Racks 1-6 Duringthese racks a change is made from the Instead of employing the catch 24for the purpose of holding the lever 25 inoperative until requiredchanges are to be effected, as hereinbefore explained, the form of catchmechanism depicted in Figure 3 may, alternatively, be adopted. Thismechanism includes a catch or trip lever 98 formed with a claw-likeformation 98a, adapted for engagement at appropriate times with. the pinor projection 25. This lever is 1 pivoted at 99 and, in a somewhatsimilar way to production of patterned to purl knitted fabric,

and the transfer cams 44, '52, 44 and 52 are moved in simultaneously atthe 1st rack.

Racks 7-12 the stitch cams 4| and 46 are operated and the 7 the catch24, is operable to release the rack lever 26 from the aforesaid timingor controlling mechanism-through the medium of intermediate connectionsincluding the curved link 34. Upon release, the rack lever 26 springsinto the path of the operating cams, one of which latter is indicated atme. Mounted upon the catch or trip lever 98 is a slide Itll which isformed with a jaw lilla. The slide is suitably'guided and retained inposition byplates 32' and IE3. A tension spring Hi4, arranged as shown,serves to control said slide. The catch ortrip lever 98 is controlled bya spring m5. Now at such times as the rack lever 20 is not required tooperate, it is held inoperative, i. e. in the position shown, with thepin or projection 25 trapped between the claw 98a. and the jaw Hlla.Whenever the said catch or trip lever is operated to release the racklever 2e, however, the slide I! springs forward into the path of acatch-tripping cam or camsone of which is represented by way of exampleat I56. The idea of providing the slide It! in conjunction with thetripping cam or cams is to prevent premature re-engagement of the catchor trip lever 38 (after release) with the rack lever 28. As will beseen, the leading end of the tripping cam IE6 is in advance of theoperating cam I90. When said tripping cam engages the end of the slideI!!! it swings the latter, and hence also the lever 98, in ananti-clockwise direction clear of the pin or projection so that thepartstake up the positions indicated in dotand-dash lines. The parts are heldin this position for a length of time depending on the circumferentialextent of the cam I66, and during this time the rack lever 29 is, ofcourse, permitted to function for a sequence of racks without beingarrested. If no tripping cam is provided in advance of an operating cam,then the pin or projection 25 will come into contact with the slide IBIand force it against the spring action. As a consequence, the catch ortrip lever 98 will be turned slightly in an anti-clockwise direction,thereby allowing the pin or projection 25 to ride past the claw 98a. Byreason of it being spring-controlled the catch or trip lever 98 willthen spring into its operative position to hold the rack leverinoperative. The tripping cam or cams is or are of the samecircumferential disposition as the first operating cam or all but one ofthe operating cams, according as to whether there are two or more. Thetripping cam or cams is or are, moreover, preferably made thinner, andis or are located underneath but at a somewhat lower level than thecorresponding operating cam or cams. In this way when a mechanism,

2, In a circular knitting machine of the double axially opposed needlecylinder type, in combination, respectively diiierent sets of machinecams, a series of different operating cams in one plane for thedifferent sets of machine cams, said operating cams being driveable intimed relation with the rotational motion of the machine, a control unitfrom which said machine cams are controlled, means operable by theoperating cams for racking round the control unit, an arrangement of campieces on said unit, and intermediate mechanism between the control unitand the machine cams for operating the latter, the aforesaid arrangementof cam pieces being such that just prior to the commencement of a cycleof operations of the said machine cams the corresponding cam pieces arerespectively at different angular distances, equivalent to differentnumbers of racks of said control unit, from the points of operation ofthe machine cams.

3. In a circular knitting machine of the double axially opposed needlecylinder type, in combination, a plurality of machine cams, anarrangement of operating cams in one plane, said operating. cams beingdriveable in timed relation with the rotational motion of the machine, acontrol unit from which said machine cams are controlled, timingmechanism, a lever movable into and out of operative relationship withthe operating cams under the control of said timing pawl and ratchetmechanism through the medium of which said lever operates to rack aroundthe control unit, an arrangement of cam pieces on said unit, andintermediate mechanisms between the control unit and the machine camsfor operating the latter, the

cycle of operations of the machine cams has been Y initiated by releaseof the lever 20 the catch is prevented from engaging the said lever andholding it inoperative until the second or last of the operating camshas acted upon the lever, according to the number of operating camsprovided, i. e. two or more in a machine having two or more feeders.

As will be appreciated, the expression points of operation of themachine cams used herein and in the appended claims is intended toinclude the points at which the cam pieces or like elements on thecontrol drum or like body act upon opposing members of the intermediatemechanisms for operating the said cams.

What I claim then is:

1. In a circular knitting machine of the double axially opposed needlecylinder type, in combination, a plurality of machine cams, anarrangement of operating cams in one plane, said operating cams beingdriveable in timed relation with the rotational motion of the machine, acontrol unit from which said machine cams are controlled, means operableby the operating cams for racking round the control unit, an arrangementof cam pieces on said. unit, and intermedi: ate mechanisms between thecontrol unit and the machine cams for operating the latter, theaforesaid arrangement of cam pieces being such thatjust prior to thecommencement of a cycle of operations of the said machine oamsthecorresponding cam pieces are respectively at different angulardistances, equivalent to different numbers of racks of said controlunit, from the points of openation of the machine cams 4:. In a circularknitting machine of the double axially opposed needle cylinder type, incombination, a pluralityof machine cams, an arrangementof operating camsin one plane, said operatin-gic'ams being driveable in timed relationwith the rotational motion of the machine, a control unit from.whichsaid machine cams are controlled, timing mechanism, a lever movable intoand out of operative relationship with the operating. cams under thecontrol of said timing mechanism, pawl and ratchet mechanism throughthefmedium of which said lever operates to rack around the control unit,an arrangement of cam pieces onsaid unit, intermediate mechanismsbetween the control unit and the machine cams foroperating the latter,the aforesaid arrangement of cam pieces being such that just priortothe. commencementof a cycle of operations of the said machine cams thecorresponding cam pieces are respectively at different angulardistances, equivalent to difierent numbers of racks of said controlunit, from the points of operation of the machine cams, and means forholding-the-aforesaid lever inoperative untilrequiredchanges are to beeffected, said last'mentioned means being operable from the timingmechanism to IEIBQJSB jthQ lever at appropriate times.

5. A combination according to claim 4, wherein the said lastmentionedmeans consists of a catch arranged so as to engagethe lever when thelatterismo'ved outwards by theoperating cams.

' 6," In.acircular'knittingmachine of the double axially opposed needlecylinder type, in combination, a plurality of machine cams, anarrangement of operating cams in one plane, said operating cams beingdriveable in timed relation with the rotational motion of the machine, acontrol unit from which said machine cams are controlled, timingmechanism, a lever movable into and out of operative relationship withthe operating cams under the control of said timing mechanism, pawl andratchet mechanism through the medium of which said lever operates torack round the control unit, an arrangement of cam pieces on said unit,intermediate mechanisms between the control unit and the machine camsfor operating the latter, the aforesaid arrangement of cam pieces beingsuch that just prior to the commencement of a cycle of operations of thesaid machine cams the corresponding cam pieces are respectively atdifferent angul ar distances, equivalent to difierent numbers of racksof said control unit, from the points of operation of the machine cams,a catch arranged to engage the aforesaid lever when it is moved outwardsby the operating cams for holding said lever inoperative until requiredchanges are to be efiected, said catch being operable from the timingmechanism to release the lever at appropriate times, and means inassociation with the catch to prevent premature re-engagement thereofwith the lever after release.

7. In a circular knitting machine of the double axially opposed needlecylinder type, in combination, a plurality of machine cams, anarrangement of operating cams in one plane, said oper ating cams beingdriveable in timed relation with with the rotational motion of themachine, a control unit from which said machine cams are controlled,timing mechanism, a lever movable into and out of operative relationshipwith the operating cams under the control of saidtiming mechanism, pawland ratchet mechanism through the medium of which said lever operates torack round the control unit, an arrangement of cam pieces on said unit,intermediate mechanisms between the control unit and the machine camsfor operating the latter, the aforesaid arrangement of cam pieces beingsuch that just prior to the commencement of a cycle of operations of thesaid machine cams the corresponding cam pieces are respectively atdiiierent angular distances, equivalent to diiierent numbers of racks ofsaid control unit, from the points of operation of the machine cams, acatch arranged to engage the aforesaid lever when it is moved outwardsby the operatingcams for holding said lever inoperative until requiredchanges are to be effected, said catch being operable from the timingmechanism to release the lever at appropriate times, a movable partcarried by the catch and at least one cam in a difierent plane from saidoperating cams for action upon the movable part to prevent prematurere-engagement of the catch with the lever after release.

8. In a circular knitting machine, in combination, a rotary plaincylinder, a superimposed coaxia1 rotary rib cylinder, a top platelocated above said rib cylinder, a plurality of machine cams, operatingcams which are mounted circumferentially and at the same level suchwiseas to be rotatable with the plain cylinder, a control unit mounted onthe aforesaid top plate and from which said machine cams are controlled,means operable by the operating cams for racking round the control unit,an arrangement of cam pieces on said unit, and intermediate mechanismsbetween the control unit and the machine cams for operating the latter,the aforesaid arrangement of cam pieces being such that just prior tothe commencement of a cycle of operations of the said machine cams thecorresponding cam pieces are respectively at different angulardistances, equivalent to different numbers of racks of said controlunit, from the points at which the cam pieces act upon opposing portionsof the intermediate. mechanisms.

9. In a circular knitting machine, in combination, a rotary plaincylinder, a superimposed coaxial rotary rib cylinder, a top platelocated above said rib cylinder, a plurality of machine cams, a seriesof operating cams which are mounted circumferentially at the same leveland in such a manner as to be rotatable with the plain cylinder, acontrol unit from which said machine cams are controlled, said unitbeing in the form of a grooved ring and mounted on the top plate, timingmechanism, a lever movable into and out of operative relationship withthe operating cams under the control of said timing mechanism, a shaftupon which said lever is mounted, pawl and ratchet mechanism through themedium of which the lever operates to rack round the control unit, saidlast mentioned mechanism including a pawl lever which is attachedto saidshaft, cam pieces arranged in the grooves of the control unit, andintermediate mechanisms between the control unit and the machine camsfor operating the latter, the aforesaid arrangement of cam pieces beingsuch that just prior to the commencement of a cycle of operations of thesaid machine cams the corresponding cam pieces are respectively atdifferent angular distances, equivalent to different numbers of racks ofsaid control unit, from the points of operation of the machine cams.

10. In a circular knitting machine of the double axially opposed needlecylinder type, in combination, a plurality of machine cams includingwelt cams and stitch cams, an arrangement of operating cams in oneplane, said operating cams being driveable in timed relation with therotational motion of the machine, a control unit from which said weltcams and stitch cams are controlled, means operable by the operatingcams for racking round the control unit, an arrangement of cam pieces onsaid unit, and intermediate mechanisms between the control unit and thewelt and stitch cams for operating said welt cams sequentiallyconjointly with operation of stitch cams, the aforesaid arrangement ofcam pieces being such that just prior to the commencement of a cycle ofoperations of the said machine cams the corresponding cam pieces arerespectively at different angular distances, equivalent to difierentnumbers of racks of said control unit, from the points of operation ofthe machine cams.

11. In a circular knitting machine, in combination, a plain cylinder, aplain cam box associated with said cylinder, an axially opposed ribcylinder, a rib cam box associated with said rib cylinder, machine camscomprising welt cams, stitch cams and needle transfer cams in said camboxes, an arrangement of operating cams in one plane, said operatingcams being driveable in timed relation with the rotational motion of themachine, a control unit from which said welt cams, stitch cams andneedle transfer cams are controlled, means operable by the operatingcams for racking round the control unit, an arrangement of cam pieces onsaid unit, and

intermediate mechanisms between the control unit and the welt cams,stitch cams and transfer camsfor operating said cams sequentially, theaforesaid arrangement of cam pieces being such that just prior to thecommencement of a cycle of operations of the said machine cams thecorresponding cam pieces, are respectively at different angulardistances, equivalent to different numbers of racks of said controlunit, from the points of operation of the machine cams.

12. In a circular knitting machine, in combination, a rotary plaincylinder, a superimposed co-axial rotary rib cylinder, a top platelocated above said rib cylinder, a plurality of machine cams, a seriesof operating cams which are mounted circumferentially at the same leveland in such a manner as to be rotatable with the plain cylinder, acontrol unit from which said machine cams are controlled, said unitbeing in the form of a grooved ring and mounted on the top plate, timingmechanism, a lever movable into and out of operative relationship withthe operating cams under the control of said timing mechanism, a shaftupon which said lever is mounted, pawl and ratchet mechanism through themedium of which the lever operates to rack round the control unit, saidlast mentioned mechanism including a pawl lever which is attached tosaid shaft, cam pieces arranged in the grooves of the control unit,intermediate mechanisms between the control unit and the machine camsfor operating the latter, the aforesaid arrangement of cam pieces beingsuch that just prior to the commencement of a cycle of operations of thesaid machine cams the corresponding cam pieces are respectively atdifferent angular distances, equivalent to different numbers of racks ofsaid control unit, from the points of operation of the machine cams, andmeans for holding the aforesaid lever inoperative until required changesare to be eifected, said last mentioned means being operable from thetiming mechanism to release the lever at appropriate times.

13. In a circular knitting machine, in combination, a rotary plaincylinder, a superimposed co-axial rotary rib cylinder, a top platelocated above said rib cylinder, a plurality of machine cams, a seriesof operating cams which are mounted circumferentially at the same leveland in such a manner as to be rotatable with the plain cylinder, acontrol unit from which said machine cams are controlled, saidunit beingin the form of a grooved ring and mounted on the top plate, timingmechanism, a lever movable into and out of operative relationship withthe operating cams under the control of said timing mechanism, a shaftupon which said lever is mounted, pawl and ratchet mechanism through themedium of which the lever operates to rack round the control unit, saidlast mentioned mechanism including a pawl lever which is attached tosaid shaft, cam pieces arranged in the grooves of the control unit,intermediate mechanisms between the control unit and the machine camsfor operating the latter, the aforesaid arrangement of cam pieces beingsuch that just prior to the commencement of a cycle of operations of thesaid machine cams the corresponding cam pieces are respectively atdifferent angular distances, equivalent to different numbers of racks ofsaid control unit, from the points of operation of the machine cams, acatch arranged to engage the aforesaid lever when it is moved outwardsby the operating cams for holding said lever inoperative until requiredchanges are to be effected, said cateh being operable from the timingmechanism to release the lever at appropriate times, and means inassociation with the catch to prevent premature re-engagement thereofwith the lever after release.

JOHN CYRIL HERBERT ITJRD.

